Marker delivery device for tissue marker placement

ABSTRACT

A marker delivery device is configured for deploying a tissue marker. The marker delivery device includes a handle having a chamber, and a cannula. According to one aspect, the cannula has a flexible portion formed by a slot arrangement having of a plurality of spaced-apart substantially parallel peripheral slots extending through the side wall of the cannula to the lumen. A marker introducer rod is movably disposed in the lumen of the cannula for deploying the mark, and has a flexible region that corresponds to the flexible portion of the cannula. According to another aspect, a retraction mechanism is mounted to the handle and is configured to facilitate a complete retraction of both the cannula and the marker introducer rod into the chamber of the housing of the handle upon an actuation of the retraction mechanism.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical devices, and, moreparticularly, to a marker delivery device for percutaneous tissue markerplacement.

2. Description of the Related Art

Tissue biopsies are commonly performed on many areas and organs of thehuman body where it is desirable to ascertain whether or not a lesion orother tissue to be biopsied is cancerous. Often, the lesion or othertissue to be biopsied is identified through use of an imaging technique,such as a computerized axial tomography (CAT) scan, ultrasonography, andmammography.

In breast biopsies, for example, the lesion typically is so small thatthe biopsy reduces its size to the extent that it is no longer visibleby the imaging method employed. In such circumstances, it is desirableto place a tissue marker at the site of the biopsy to enable the medicalpractitioner subsequently to locate the lesion quickly and accurately inthe event complete removal of the affected tissue is indicated. Thetissue marker is placed at the biopsy site, for example, by a markerdelivery device having a needle cannula that houses the tissue marker.

In some marker delivery devices, the marker may not be completelyejected from the cannula, or may be drawn back into or toward thecannula by the vacuum created upon the withdrawal of the cannula, whichresults in the marker being moved from the intended site, leading toinaccurate identification of the location of the biopsy area. Anotherissue is the safe disposal of the marker delivery device after use,particularly the safe disposal of the cannula portion of the markerdelivery device that is inserted into the tissue of the patient, whichtypically has a sharp point.

SUMMARY OF THE INVENTION

The invention provides, according to one aspect thereof, a markerdelivery device configured to fully deliver the tissue marker at adelivery site in the patient where the tissue marker is less likely tomigrate, which is achieved by delivering the tissue marker via a rigidcannula having a flexible portion for directing the distal end of thecannula, for example, into tissue adjacent a biopsy site. The inventionprovides, according to another aspect thereof, a marker delivery deviceconfigured to facilitate the safe disposal of the marker delivery deviceafter use. The marker delivery device may be used, for example, inassociation with various imaging systems, such as X-ray, ultrasound, MRIetc.

The invention, in one form thereof, is directed to a marker deliverydevice configured for deploying a tissue marker. The marker deliverydevice includes a handle having a chamber. A cannula is configured forholding the tissue marker for deployment. The cannula has a side wallsurrounding a lumen that extends along a lengthwise extent of thecannula. The cannula has a flexible portion formed by a slot arrangementhaving of a plurality of peripheral slots extending through the sidewall of the cannula to the lumen. The plurality of peripheral slots isspaced apart to be substantially parallel along the lengthwise extent ofthe cannula to facilitate a flexure at the flexible portion of thecannula. A marker introducer rod is movably disposed in the lumen of thecannula. The marker introducer rod has a flexible region thatcorresponds to the flexible portion of the cannula. A deploymentmechanism is mounted to the handle and configured to displace the markerintroducer rod for deploying the tissue marker upon an actuation of thedeployment mechanism. A retraction mechanism is mounted to the handleand is configured to facilitate a complete retraction of both thecannula and the marker introducer rod into the chamber of the housing ofthe handle upon an actuation of the retraction mechanism.

The invention, in another form thereof, is directed to a marker deliverydevice configured for deploying a tissue marker. The marker deliverydevice includes a handle configured to be grasped by a user. A cannulahas a proximal end and a distal end, the proximal end being coupled tothe handle. The cannula is substantially rigid and has a side wallsurrounding a lumen that extends along a lengthwise extent of thecannula. The cannula has a flexible portion formed by a slot arrangementhaving of a plurality of peripheral slots extending through the sidewall of the cannula to the lumen. The slots of the plurality ofperipheral slots are spaced apart to be substantially parallel along thelengthwise extent of the cannula to facilitate a flexure at the flexibleportion of the cannula. A marker introducer rod is movably disposed inthe lumen of the cannula to effect a deployment of the tissue markerfrom the distal end of the cannula. The marker introducer rod has anactuation end and a marker deployment end, and a flexible region thatcorresponds to the flexible portion of the cannula.

The invention, in another form thereof, is directed to a marker deliverydevice configured for deploying a tissue marker. The marker deliverydevice includes a handle configured to be to be grasped by a user. Thehandle includes a housing having a front end and a back end, with achamber located between the front end and the back end, and having ahole leading from the chamber to the exterior of the handle. A cannulahas a proximal end, a distal end, and a lumen extending along alengthwise extent of the cannula between the proximal end and the distalend. The cannula is positioned in the handle such that the cannularetractably extends through the hole beyond the front end of thehousing. A marker introducer rod is movably disposed in the lumen of thecannula to effect a deployment of the tissue marker from the distal endof the cannula. The marker introducer rod has an actuation end and amarker deployment end. A deployment mechanism is mounted to the housing.The deployment mechanism is coupled to the actuation end of the markerintroducer rod. The deployment mechanism is configured to displace themarker introducer rod for deploying the tissue marker upon an actuationof the deployment mechanism. A retraction mechanism is mounted to thehousing, and is coupled to the proximal end of the cannula. Theretraction mechanism is configured to facilitate a complete retractionof both the cannula and the marker introducer rod into the chamber ofthe housing of the handle upon an actuation of the retraction mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a perspective view of a marker delivery device configured fordeploying a tissue marker in accordance with an embodiment of thepresent invention;

FIG. 2 is a section view of a portion of the marker delivery device ofFIG. 1 taken along plane 2-2;

FIG. 3 is a section view of a portion of the marker delivery device ofFIG. 1 taken along plane 3-3;

FIG. 4A is a top view of a portion of the cannula of the marker deliverydevice of FIG. 1 depicting a flexible portion of the cannula;

FIG. 4B is a side view of the flexible portion of the cannula of FIG.4A, showing in phantom lines the flexure of the flexible portion of thecannula relative to non-flexure;

FIG. 4C is an end view of the cannula of FIG. 4A from the perspective oflooking into the lumen of the cannula from the distal end of thecannula, also showing in phantom lines the flexure of the flexibleportion of the cannula relative to non-flexure;

FIG. 5 is a top view of an alternative configuration of the flexibleportion of the marker delivery device of FIG. 1;

FIG. 6 is a top view of another alternative configuration of theflexible portion of the cannula of the marker delivery device of FIG. 1;

FIG. 7 is a side view of a portion of the marker introducer rod of themarker delivery device of FIG. 1, showing the actuation end, the markerdeployment end, and the flexible region;

FIG. 8 is a perspective view of the marker delivery device of FIG. 1used in conjunction with a biopsy device, showing a flexure of flexibleportion of the cannula;

FIG. 9 is a perspective view of the marker delivery device of FIG. 1following complete retraction of the cannula and marker introducer rodinto the longitudinal chamber of the housing of the handle;

FIG. 10 is a perspective view of a marker delivery device configured fordeploying a tissue marker in accordance with another embodiment of thepresent invention;

FIG. 11 is a section view of the marker delivery device of FIG. 10 takenalong plane 11-11, showing the deployment mechanism in an initialposition;

FIG. 12 is a section view of the marker delivery device of FIG. 10,showing the deployment mechanism in a marker deployed position;

FIG. 13 is a section view of the marker delivery device of FIG. 10,showing the deployment mechanism in a marker introducer rod initialretraction position;

FIG. 14 is a section view of the marker delivery device of FIG. 10,showing the deployment mechanism in a marker introducer rod post-initialretraction position; and

FIG. 15 is a section view of a portion of the marker delivery device ofFIG. 10 taken along plane 15-15, depicting the cannula retractionmechanism.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate embodiments of the invention, and such exemplifications arenot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1-3, thereis shown a marker delivery device 10 configured for deploying a tissuemarker 12, in accordance with an embodiment of the present invention.

Marker delivery device 10 includes a handle 14, a cannula 16, a markerintroducer rod 18, a deployment mechanism 20 and a retraction mechanism22.

Handle 14 is configured to be grasped by a user, i.e., is of anappropriate size and shape to be grasped by the hand of the user ofmarker delivery device 10. Handle 14 includes a housing 24 having afront end 24-1, a back end 24-2 and a side wall 24-3, with alongitudinal chamber 26 located between front end 24-1 and back end 24-2that is surrounded by side wall 24-3. A hole 24-4 leads from chamber 26through front end 24-1 of housing 24 to the exterior of handle 14. Atrigger slot 24-5 extends through side wall 24-3 of housing 24.

Cannula 16 is configured for holding tissue marker 12 for deploymentinto a tissue mass of a patient, and may be in the form of a hollowneedle. Cannula 16 is positioned in handle 14 such that cannula 16extends through the hole 24-4 beyond the front end 24-1 of housing 24prior to marker deployment. Cannula 16 has a proximal end 16-1 and adistal end 16-2, with the proximal end 16-1 being coupled to handle 14.Cannula 16 has a side wall 16-3 that surrounds a lumen 16-4 that extendsalong a lengthwise extent 28 along a longitudinal axis 16-5 of cannula16. Cannula 16 is substantially rigid, and may be made, for example,from a metallic material, such as for example, stainless steel, nitinol,a nickel-chromium alloy, titanium, etc.

Referring also to FIGS. 4A-4C, cannula 16 has a flexible portion 30formed by a slot arrangement 32 having of a plurality of peripheralslots 34 arranged circumferentially around cannula 16. Slot arrangement32 may be formed in cannula 16, for example, by making cuts in cannula16, such as through the use of a cutting laser. In the presentembodiment, flexible portion 30 of cannula 16 is located closer to thedistal end 16-2 of cannula 16 than to proximal end 16-1 of cannula 16.The plurality of peripheral slots 34 extends through the side wall 16-2of cannula 16 to lumen 16-4. Also, as illustrated in FIG. 4C, in thepresent embodiment a circumferential extent 34-1 of each of the slots ofthe plurality of peripheral slots 34 of slot arrangement 32 isapproximately two-thirds of the total circumference of cannula 16.

As illustrated in FIGS. 4A and 4B, in the present embodiment theplurality of peripheral slots 34 are spaced apart from one another to besubstantially parallel along the lengthwise extent 28 of cannula 16 tofacilitate a flexure at flexible portion 30 of cannula 16. FIG. 4B showsin phantom lines the flexure of the flexible portion 30 of cannula 16relative to a non-flexure of cannula 16. As illustrated in FIGS. 4B and4C, the configuration of the plurality of peripheral slots 34 (e.g., thecircumferential placement of the slots along cannula 16) may be selectedso that the flexure occurs along a single predetermined plane 36. In thepresent embodiment, for example, each of the substantially parallelplurality of peripheral slots 34 is arranged to be orthogonal to thelongitudinal axis 16-5 of cannula 16.

The configuration of the plurality of peripheral slots 34 and thematerial forming cannula 16 may be selected such that the flexure doesnot result in a permanent deformation of cannula 16. For example, a slotwidth 34-2 relative to longitudinal axis 16-5 of the slots, thecircumferential extent 34-1 of the slots, the axial placement of theslots along cannula 16, and the material used to form cannula 16 may beselected, through empirical studies and/or through materials analysis,so that flexible portion 30 formed by slot arrangement 32 will flex(e.g., bend at an acute angle with respect to longitudinal axis 16-5)when the distal end 16-2 of cannula 16 is acted on by an external force(F), and then return to the pre-deflected state, e.g., straight alonglongitudinal axis 16-5, when the external force (F) is removed.

FIG. 5 shows another slot arrangement 38 that may be used as analternative to slot arrangement 32 shown in FIGS. 4A-4C. Slotarrangement 38 may be formed in cannula 16, for example, by making cutsin cannula 16, such as through the use of a cutting laser. Slotarrangement 38 includes of a plurality of peripheral slots 40 arrangedcircumferentially around cannula 16. The plurality of peripheral slots40 include a first set of peripheral slots 42-1 having a firstcircumferential extent 44-1 and a second set of peripheral slots 42-2having a second circumferential extent 44-2. The first circumferentialextent 44-1 of the first set of peripheral slots 42-1 iscircumferentially staggered with respect to the second circumferentialextent 44-2 of the second set of peripheral slots 42-2.

FIG. 6 shows another slot arrangement 46 that may be used as a furtheralternative to slot arrangement 32 shown in FIGS. 4A-4C, and includesthe plurality of peripheral slots 34 arranged circumferentially aroundcannula 16, but in addition includes an axial slot 48 that extends alongthe lengthwise extent 28 of cannula 16 to link at least a portion, orall, of the plurality of peripheral slots 34 in a continuous slotarrangement. Slot arrangement 46 may be formed in cannula 16, forexample, by making cuts in cannula 16, such as through the use of acutting laser.

Referring again to FIGS. 2 and 3, marker introducer rod 18 is movablydisposed in lumen 16-4 of cannula 16 to effect a deployment of tissuemarker 12 from the distal end 16-2 of cannula 16. Referring also to FIG.7, marker introducer rod 18 has an actuation end 18-1 and a markerdeployment end 18-2, and has a flexible region 50 that corresponds tothe flexible portion 30 of cannula 16. Accordingly, as flexible portion30 of cannula 16 flexes, the flexible region 50 also flexes, whileretaining the ability of marker introducer rod 18 to move longitudinallyalong lumen 16-4 to effect a deployment of tissue marker 12.

The flexible region 50 of marker introducer rod 18 may be formed as aflexible metallic element or a flexible plastic element, which in thepresent embodiment may be of reduced diameter with respect to a diameterof the remainder of marker introducer rod 18. Also, the remainder ofmarker introducer rod 18 may be formed from metal or plastic.

FIG. 8 illustrates an exemplary implementation of marker delivery device10 with respect to the flexible portion 30 of cannula 16, and moreparticularly shows a portion of an exemplary breast biopsy device 52having the driver removed (not shown) that drives a cutter and vacuumunit in harvesting a tissue sample via a biopsy needle 54. Thereafter,cannula 16 of marker delivery device 10 is inserted through the lumen ofbiopsy needle 54 for placing tissue marker 12 in the tissue of thepatient.

Biopsy needle 54 has a side sample notch 56 leading to a sample chamber58 located at the lumen of biopsy needle 54. As cannula 16 is advancedin the lumen of biopsy needle 54 to the end of sample chamber 58, aramped surface 58-1 at the end of sample chamber 58 exerts force (F) todeflect the distal end 16-2 of cannula 16 resulting in a flexure offlexible portion 30 of cannula (see also FIGS. 4A-4C), thereby exposingthe distal end 16-2 of cannula 16 to sample notch 56. With a furtheradvancement of cannula 16 in the lumen of biopsy needle 54, as shown inFIG. 8, the distal end 16-2 of cannula 16 extends through sample notch56 to penetrate tissue adjacent the biopsy site.

Thereafter, an advancement of marker introducer rod 18 in lumen 16-4 ofcannula 16 (see, e.g., FIG. 3) causes tissue marker 12 to be deployedinto the tissue surrounding the biopsy site. flexible region 50 ofmarker introducer rod 18 (see, e.g., FIG. 7) conforms to the shape offlexible portion 30 of cannula 16, before, during and after the flexureof flexible portion 30 of cannula 16.

Alternatively, the distal end 16-2 of cannula 16 may be exposed tosample notch 56 without extending though sample notch 56, and tissuemarker 12 may be deployed though sample notch 56 of biopsy needle 54into the biopsy cavity.

Referring again to FIGS. 1-3, deployment mechanism 20 is mounted tohousing 24 of handle 14 and is configured to displace marker introducerrod 18 for deploying tissue marker 12 upon an actuation of deploymentmechanism 20 by the user. In general, deployment mechanism 20 isconfigured to limit marker delivery device 10 to a single use for markerdeployment. FIGS. 1 and 2 show deployment mechanism 20 in an initialposition 60 (marker not deployed) and FIG. 3 shows deployment mechanism20 in a marker deployed position 62.

More particularly, deployment mechanism 20 includes an introducer rodguide block 64, a marker deployment trigger 66, and a first shear member68. Introducer rod guide block 64 is fixedly attached to the actuationend 18-1 of marker introducer rod 18, such as by molding a portion ofmarker introducer rod 18 into introducer rod guide block 64, and isslidably disposed in chamber 26 of housing 24. Marker deployment trigger66 is accessible at an exterior of housing 24 of handle 14. Markerdeployment trigger 66 is mounted to housing 24 for siding movement alongtrigger slot 24-5 of housing 24 from the initial position 60 shown inFIGS. 1 and 2 toward the front end 24-1 of housing 24 to positiondeployment mechanism 20 at the marker deployed position 62.

In the present embodiment, marker deployment trigger 66 and introducerrod guide block 64 are linked by first shear member 68. First shearmember 68 extends from marker deployment trigger 66 and resides in arecess 70 located in introducer rod guide block 64. Thus, an actuationof marker deployment trigger 66 causes first shear member 68 to displaceintroducer rod guide block 64, which in turn displaces marker introducerrod 18 along the lengthwise extent 28 of cannula 16 to deploy tissuemarker 12 from lumen 16-4 of cannula 16. First shear member 68 has aregion of reduced cross section dimension 68-1, e.g., an annular groove,to provide a shear location.

An outer contour of introducer rod guide block 64 may be selected to beslidably received in a like-inner contour of longitudinal chamber 26 ofhousing 24 of handle 14. Accordingly, in embodiments where the outercontour of introducer rod guide block 64 and the like-inner contour oflongitudinal chamber 26 are non-circular, introducer rod guide block 64prevents rotation of marker introducer rod 18 with respect to housing 24of handle 14, thus maintaining a constant orientation of markerintroducer rod 18 relative to handle 14.

Also, in embodiments where the outer contour of introducer rod guideblock 64 and the like-inner contour of longitudinal chamber 26 arecircular, recess 70 of introducer rod guide block 64 may be in the formof a circumferential groove to facilitate a change in angular position,i.e., rotation, of marker introducer rod 18 with respect to housing 24of handle 14. In such case, a rotator, e.g., knob, (not shown)positioned external to handle 14 may be coupled to introducer rod guideblock 64 to effect a change in orientation of marker introducer rod 18relative to handle 14.

As best shown in FIG. 2, deployment mechanism 20 may further include alock mechanism 72 to lock marker deployment trigger 66 in the markerdeployed position 62 after tissue marker 12 has been deployed. In thepresent embodiment, lock mechanism 72 includes a first lock member 72-1formed on, or attached to, marker deployment trigger 66 and includes asecond lock member 72-2 formed on, or attached to, housing 24. Inoperation, first lock member 72-1 permanently engages second lock member72-2 when marker deployment trigger 66 is positioned in the markerdeployed position 62, thereby limiting marker delivery device 10 to asingle marker deployment operation.

One of first lock member 72-1 and second lock member 72-1 may be, forexample, a lock channel and the other of first lock member 72-1 andsecond lock member 72-2 may be a spring-loaded insert member thatengages the lock channel when marker deployment trigger 66, and in turnmarker introducer rod 18, is positioned in marker deployed position 62.In the present embodiment shown in FIG. 2, for example, first lockmember 72-1 is formed as a lock channel in marker deployment trigger 66,and second lock member 72-2 is in the form of a spring-loaded pin thatengages the lock channel when marker deployment trigger 66 is slidtoward the front end 24-1 of housing 24 to position deployment mechanism20, and in turn marker introducer rod 18, in marker deployed position62. As a further example, when second lock member 72-2 is formed as alock channel in housing 24, the lock channel may be formed by, orintegral with, trigger slot 24-5, and first lock member 72-1 as aspring-loaded insert member may be a cantilevered arm having aprotrusion that engages the lock channel when marker deployment trigger66 is positioned in marker deployed position 62.

Again referring to FIGS. 1-3, retraction mechanism 22 is mounted tohousing 24 of handle 14 and is configured to facilitate a completeretraction of both cannula 16 and marker introducer rod 18 into chamber26 of housing 24 of handle 14 upon an actuation of retraction mechanism22 by the user, which most likely will occur following deployment oftissue marker 12. Retraction mechanism 22 is configured to preventcannula 16 and marker introducer rod 18 from extending outside chamber26 of housing 24 of handle 14 after the complete retraction of cannula16 and marker introducer rod 18 into chamber 26, thus facilitating thesafe disposal of marker delivery device 10, and alleviating concernabout the accidental puncturing of medical personnel, or the patient,following the use of marker delivery device 10.

More particularly, retraction mechanism 22 includes a retraction trigger74, a cannula guide block 76, a second shear member 78, and a spring 80.Retraction trigger 74 may be in the form of a push button that isaccessible at the exterior of the housing 24, e.g., through a hole 24-7in side wall 24-3. Cannula guide block 76 is fixedly attached to theproximal end 16-1 of cannula 16, such as by molding a portion of cannula16 into cannula guide block 76. Cannula guide block 76 is slidablydisposed in longitudinal chamber 26 of housing 24. In the presentembodiment, second shear member 78 is formed as an extension ofretraction trigger 74.

As best shown in FIG. 3, retraction trigger 74 and cannula guide block76 are linked by second shear member 78 that is resident in a recess 82located in cannula guide block 76, thus holding cannula guide block 76stationary, e.g., axially stationary, relative to housing 24 of handle14. Spring 80 is located between the front end 24-1 of housing 24 andcannula guide block 76, with spring 80 being in a compressed state priorto actuation of retraction trigger 74, thus providing a preload oncannula guide block 76.

An outer contour of cannula guide block 76 may be selected to beslidably received in an inner like-contour of longitudinal chamber 26 ofhousing 24 of handle 14. Accordingly, in embodiments where the outercontour of cannula guide block 76 and the inner like-contour oflongitudinal chamber 26 are non-circular, cannula guide block 76prevents rotation of cannula 16 with respect to housing 24 of handle 14,thus maintaining a constant orientation of cannula 16 relative to handle14.

However, in embodiments where the outer contour of cannula guide block76 and the inner like-contour of longitudinal chamber 26 are circular,recess 82 of cannula guide block 76 may be in the form of acircumferential groove to facilitate a change in angular position, i.e.,rotation, of cannula 16 with respect to housing 24 of handle 14, thusfacilitating a changeable orientation of cannula 16 relative to handle14. In such case, cannula 16 may be manually rotated by grasping cannula16 and turning. Alternatively, a rotator, e.g., knob, (not shown)positioned external to handle 14 may be coupled to guide block 76 toeffect a change in orientation of cannula 16 relative to handle 14.

An actuation of retraction trigger 74 causes a complete retraction ofboth cannula 16 and marker introducer rod 18 into chamber 26 of housing24 of handle 14. More particularly, as shown in FIG. 3, second shearmember 78 has a region of reduced cross section dimension 78-1, e.g., anannular groove, to provide a shear location. Initially, the region ofreduced cross section dimension 78-1 of second shear member 78 iscontained within the hole 24-7 formed in side wall 24-3, therebyproviding additional support at the region of reduced cross sectiondimension 78-1.

In the present embodiment, an actuation (depressing) of retractiontrigger 74 radially displaces second shear member 78 causing secondshear member 78 to shear. More particularly, by depressing retractiontrigger 74, the region of reduced cross section dimension 78-1 of secondshear member 78 enters longitudinal chamber 26 through side wall 24-3 ofhousing 24, such that the region of reduced cross section dimension 78-1of second shear member 78 is no longer supported by side wall 24-3, andwhereby the spring force exerted by spring 80 overcomes the shearresistance of the region of reduced cross section dimension 78-1 ofsecond shear member 78. The shearing of second shear member 78 resultsin a release of spring 80 from the compressed state shown in FIGS. 1-3to force cannula guide block 76 to move toward the back end 24-2 ofhousing 24 to begin an initial retraction of cannula 16, and wherein acontinued decompression of spring 80 causes cannula guide block 76 toimpact introducer rod guide block 64 to shear first shear member 68,whereby beginning a simultaneous retraction of both cannula 16 andmarker introducer rod 18 into chamber 26 of housing 24 of handle 14. Thesimultaneous retraction of both cannula 16 and marker introducer rod 18into handle 14 terminates after both cannula 16 and marker introducerrod 18 are completely contained in longitudinal chamber 26 of housing 24of handle 14, as illustrated in FIG. 9.

Alternatively, a spacing device 84 (see FIG. 1) may be positionedbetween introducer rod guide block 64 and cannula guide block 76.Spacing device 84 has a length along the lengthwise extent 28 such thatcannula guide block 76 is in operable contact with introducer rod guideblock 64 when introducer rod guide block 64 is positioned in the markerdeployed position 62, such that first shear member 68 and second shearmember 78 are sheared substantially simultaneously when retractiontrigger 74 displaced, resulting in a complete simultaneous retraction ofboth cannula 16 and marker introducer rod 18 into chamber 26 of housing24.

FIGS. 10-15 depict another embodiment of the invention, depicting amarker delivery device 110 that includes a handle 112, cannula 16,marker introducer rod 18, a deployment mechanism 114 and a cannularetraction mechanism 116. Cannula 16 and marker introducer rod 18 may beconfigured as previously described, and thus for brevity the fulldetails of their operation will not be repeated here. Marker deliverydevice 110 functionally differs from the embodiment of marker deliverydevice 10, in that deployment mechanism 114 of marker delivery device110 may be configured to facilitate a full retraction of markerintroducer rod 18 prior to beginning the retraction of cannula 16effected by cannula retraction mechanism 116.

Handle 112 is configured of an appropriate size and shape to be graspedby the hand of the user of marker delivery device 110. Handle 112includes a housing 118 having a front end 118-1, a back end 118-2 and aside wall 118-3, with a longitudinal chamber 120 located between frontend 118-1 and back end 118-2 that is surrounded by side wall 118-3. Ahole 118-4 leads from longitudinal chamber 120 through the front end118-1 of housing 118 to the exterior of handle 112. Cannula 16 ispositioned in handle 112 such that cannula 16 initially extends throughhole 118-4 beyond the front end 118-1 of housing 118 prior to markerdeployment. A trigger slot 118-5 extends through side wall 118-3 ofhousing 118.

Deployment mechanism 114 is mounted to housing 118 of handle 112 and isconfigured to displace marker introducer rod 18 for deploying tissuemarker 12 upon an actuation of deployment mechanism 114 by the user.FIGS. 10 and 11 show deployment mechanism 114 in an initial position 121(unused, marker not deployed), FIG. 12 shows deployment mechanism 114 ina marker deployed position 122, FIG. 13 shows deployment mechanism 114in a marker introducer rod initial retraction position 124, and FIG. 14shows deployment mechanism 114 in a marker introducer rod post-initialretraction position 126.

Deployment mechanism 114 includes an introducer rod guide block 128, amulti-stage marker deployment trigger 130, a first shear member 132, andan introducer rod retraction spring 133. First shear member 132 has aregion of reduced cross section dimension 132-1, e.g., an annulargroove, to provide a shear location. Introducer rod guide block 128 isattached to the actuation end 18-1 of marker introducer rod 18, and isslidably disposed in longitudinal chamber 120 of housing 118. Markerdeployment trigger 130 is accessible at an exterior of housing 118 ofhandle 112. Marker deployment trigger 130 includes an inner sleeve 130-1and an outer actuator 130-2. Marker deployment trigger 130 is mounted tohousing 118 for siding movement along trigger slot 118-5.

FIGS. 11-14 show various stages of movement of inner sleeve 130-1 and anouter actuator 130-2 of marker deployment trigger 130. In the presentembodiment, marker deployment trigger 130 and introducer rod guide block128 are linked by first shear member 132. First shear member 132 extendsfrom inner sleeve 130-1 of marker deployment trigger 130 and resides ina recess 134 located in introducer rod guide block 128.

Initially, as shown in FIG. 11, inner sleeve 130-1 and outer actuator130-2 of marker deployment trigger 130 are linked by a drive tab 136mounted to inner sleeve 130-1 that engages a drive slot 138 formed inouter actuator 130-2, so that inner sleeve 130-1 and outer actuator130-2 initially move concurrently. Drive slot 138 is defined by adownward facing lip 140 that separates drive slot 138 from an elongateintroducer rod retraction slot 142. Drive tab 136 may be hinge-mounted,e.g., by a linking membrane, to inner sleeve 130-1. Drive tab 136includes an upwardly extending protrusion 136-1 that is initiallyengaged with lip 140 in drive slot 138. Introducer rod retraction spring133 is positioned between cannula retraction mechanism 116 andintroducer rod guide block 128 under slight compression, and moreparticularly, between introducer rod guide block 128 and cannula guideblock 156.

Referring to FIG. 12, an actuation of marker deployment trigger 130 bysliding outer actuator 130-2 of marker deployment trigger 130 toward thefront end 118-1 of housing 118 of handle 112 causes inner sleeve 130-1to move first shear member 132 longitudinally along longitudinal chamber120 to displace introducer rod guide block 128, which in turn displacesmarker introducer rod 18 along the lengthwise extent 28 of cannula 16 todeploy tissue marker 12 from lumen 16-4 of cannula 16 when the markerdeployed position 122 depicted in FIG. 12 is reached. At this stage,introducer rod retraction spring 133 is being compressed. Housing 118includes an indicator line 144, such that when a leading edge 146 ofinner sleeve 130-1 aligns with indicator line 144 to indicate that themarker deployed position 122 has been reached, the user is assured of acomplete deployment of tissue marker 12 out of the distal end 16-2 ofcannula 16.

Also, as depicted in FIG. 12, when marker deployment trigger 130 ispositioned at marker deployed position 122, drive tab 136 is positionedover a retraction channel 148 in housing 118. A further sliding of outeractuator 130-2 of marker deployment trigger 130 toward the front end118-1 of housing 118 of handle 112 causes lip 140 forming a trailingedge of drive slot 138 to force protrusion 136-1 of drive tab 136 totwist forward into a deformation downward into a retraction channel 148formed in housing 118 of handle 112, thereby allowing lip 140 to beginto pass over protrusion 136-1 of drive tab 136. At this stage,introducer rod retraction spring 133 has reached maximum compression.

As depicted in FIG. 13, the further sliding of outer actuator 130-2 ofmarker deployment trigger 130 toward the front end 118-1 of housing 118of handle 112 causes lip 140 to pass over the upward protrusion 136-1 ofdrive tab 136, thereby allowing drive tab 136 to regain its originalgeometry with respect inner sleeve 130-1, thereby moving upwardly out ofretraction channel 148. This action occurs when the leading edge 150 ofouter actuator 130-2 aligns with indicator line 152 of inner sleeve130-1. At this stage, introducer rod retraction spring 133 starts todecompress. Accordingly, a portion of deployment mechanism 114, e.g.,inner sleeve 130-1, outer actuator 130-2, drive tab 136, lip 140, andretraction channel 148 of deployment mechanism 114, also functions as anintroducer rod retraction mechanism 153 for marker introducer rod 18.

As depicted in FIG. 14, with upward protrusion 136-1 of drive tab 136fully released from retraction channel 148 and upward protrusion 136-1of drive tab 136 being positioned in introducer rod retraction slot 142,the decompression of introducer rod retraction spring 133 forcesintroducer rod guide block 128 toward the back end 118-2 of housing 118(see FIG. 10), and in turn marker introducer rod 18 and inner sleeve130-1 are returned toward their initial positions as depicted in FIGS.10 and 11. The spring force provided by introducer rod retraction spring133 may be selected, for example, such that the impact of inner sleeve130-1 with end wall 118-6 of housing 118 causes first shear member 132to shear at the region of reduced cross section dimension 132-1, therebyfacilitating a complete retraction of marker introducer rod 18 intolongitudinal chamber 120, prior to initiating retraction of cannula 16.

Alternatively, the spring force provided by introducer rod retractionspring 133 may be selected, for example, such that the impact of innersleeve 130-1 with end wall 118-6 of housing 118 stops the retraction ofmarker introducer rod 18 into longitudinal chamber 120 after a partialretraction of marker introducer rod 18, prior to initiating retractionof cannula 16.

Also, as depicted in FIG. 14, at this stage outer actuator 130-2 ofmarker deployment trigger 130 is no longer linked to inner sleeve 130-1.Thus, a subsequent extension of marker introducer rod 18 by actuation ofouter actuator 130-2 of marker deployment trigger 130 is prevented,thereby rendering marker delivery device 110 usable for only a singletissue marker deployment.

Referring again also to FIG. 10 in relation to FIGS. 14 and 15, cannularetraction mechanism 116 is mounted to housing 118 of handle 112 and isconfigured to facilitate a complete retraction of cannula 16 intolongitudinal chamber 120 of housing 118 of handle 112 upon an actuationof cannula retraction mechanism 116 by the user, which most likely willoccur following deployment of tissue marker 12. FIG. 15 shows cannularetraction mechanism 116, with marker introducer rod 18 in markerdeployed position 122. Cannula retraction mechanism 116 is configured toprevent cannula 16 and marker introducer rod 18 from extending outsidelongitudinal chamber 120 of housing 118 of handle 112 after the completeretraction of cannula 16 and marker introducer rod 18 into longitudinalchamber 120, thus facilitating the safe disposal of marker deliverydevice 110, and alleviating concern about the accidental puncturing ofmedical personnel, or the patient, following the use of marker deliverydevice 110.

Cannula retraction mechanism 116 includes a retraction trigger 154, acannula guide block 156, a second shear member 158, and a cannularetraction spring 160. Retraction trigger 154 may be in the form of apush button that is accessible at the exterior of housing 118, e.g.,through a hole 118-7 in side wall 118-3. Cannula guide block 156 isattached to the proximal end 16-1 of cannula 16. Cannula guide block 156is slidably disposed in longitudinal chamber 120 of housing 118. In thepresent embodiment, second shear member 158 is formed as an extension ofretraction trigger 154.

Retraction trigger 154 and cannula guide block 156 are linked by secondshear member 158 that is resident in a recess 162 located in cannulaguide block 156, thus holding cannula guide block 156 stationaryrelative to housing 118 of handle 112. Cannula retraction spring 160 islocated between the front end 118-1 of housing 118 and cannula guideblock 156, with cannula retraction spring 160 being in a compressedstate prior to actuation of retraction trigger 154, thus providing apreload on cannula guide block 156.

An actuation of retraction trigger 154 causes a complete retraction ofcannula 16 into longitudinal chamber 120 of housing 118 of handle 112.More particularly, as shown in FIG. 15, initially, the region of reducedcross section dimension 158-1 of second shear member 158 is supported byside wall 118-3, thereby providing additional support at the region ofreduced cross section dimension 158-1. An actuation (depressing) ofretraction trigger 154 radially displaces second shear member 158causing the region of reduced cross section dimension 158-1 of secondshear member 158 to enter longitudinal chamber 120 through side wall118-3 of housing 118, such that the region of reduced cross sectiondimension 158-1 of second shear member 158 is no longer supported by theside wall 118-3, and whereby the spring force exerted by cannularetraction spring 160 overcomes the shear resistance of the region ofreduced cross section dimension 158-1 of second shear member 158. Theshearing of second shear member 158 results in a release of cannularetraction spring 160 from the compressed state shown to force cannulaguide block 156 to move toward the back end 118-2 of housing 118 tocomplete a full retraction of cannula 16 into longitudinal chamber 120of housing 118 of handle 112.

In the event of a partial retraction of marker introducer rod 18, or inthe event that the user does not perform the previously describedretraction of marker reducer rod, into longitudinal chamber 120 ofhousing 118 of handle 112 prior to actuation of retraction trigger 154(as depicted in FIG. 15), the continued decompression of cannularetraction spring 160 causes cannula guide block 156 to impactintroducer rod guide block 128 to shear first shear member 132, wherebyfacilitating a full simultaneous retraction of both cannula 16 andmarker introducer rod 18 into longitudinal chamber 120 of housing 118 ofhandle 112.

The retraction process is completed when both cannula 16 and markerintroducer rod 18 are completely contained in longitudinal chamber 120of housing 118 of handle 112.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

1-23. (canceled)
 24. A marker delivery device configured for deploying atissue marker, comprising: a handle including a housing having a frontend and a back end, with a chamber located between the front end and theback end, and having a hole leading from the chamber to the exterior ofthe handle; a cannula having a proximal end, a distal end, and a lumen,the cannula being positioned in the handle such that the cannularetractably extends through the hole beyond the front end of thehousing; and a retraction mechanism mounted to the housing, theretraction mechanism being coupled to the proximal end of the cannula,the retraction mechanism being configured to store a retraction force,and configured to facilitate a retraction of the cannula into thechamber of the housing of the handle upon an actuation of the retractionmechanism, the retraction mechanism including a shear member having ashear region of reduced cross section dimension, the shear memberconfigured to be displaced by a user to expose the shear region to theretraction force to shear the shear member at the shear region to enablethe retraction. 25-45. (canceled)
 46. The marker delivery device ofclaim 24, wherein the retraction mechanism includes: a retractiontrigger accessible at the exterior of the housing, the retractiontrigger configured to displace the shear member and release theretraction force; and a cannula guide block attached to the proximal endof the cannula, the retraction force being applied to the cannula guideblock, the cannula guide block being slidably disposed in the chamber ofthe housing, the retraction trigger being linked to the cannula guideblock by the shear member to hold the cannula guide block stationaryrelative to the housing of the handle prior to actuation of theretraction trigger, and the retraction mechanism configured such thatwhen the retraction trigger is actuated, the shear member is sheared atthe shear region to permanently disconnect the retraction trigger fromthe cannula guide block.
 47. The marker delivery device of claim 46, theretraction mechanism including a spring located between the front end ofthe housing and the cannula guide block, the spring being in acompressed state prior to actuation of the retraction trigger to providea preload of the retraction force on the cannula guide block, andconfigured to decompress to effect the retraction of the cannula guideblock within the housing to shear the shear member at the shear regionwhen the retraction trigger is actuated.
 48. The marker delivery deviceof claim 24, further comprising: a marker introducer rod disposedcoaxially with the cannula, and configured to deploy the tissue markerfrom the distal end of the cannula, the marker introducer rod having anactuation end and a marker deployment end; a deployment mechanismmounted to the housing, the deployment mechanism being coupled to theactuation end of the marker introducer rod, the deployment mechanismbeing configured to displace the marker introducer rod for deploying thetissue marker upon an actuation of the deployment mechanism; and theretraction mechanism configured to facilitate a complete retraction ofboth the cannula and the marker introducer rod into the chamber of thehousing of the handle upon an actuation of the retraction mechanism. 49.A marker delivery device configured for deploying a tissue marker,comprising: a handle including a housing having a front end and a backend, with a chamber located between the front end and the back end, andhaving a hole leading from the chamber to the exterior of the handle; acannula having a proximal end, a distal end, and a lumen, the cannulabeing positioned in the handle such that the cannula retractably extendsthrough the hole beyond the front end of the housing; a markerintroducer rod coaxial with the cannula, the marker introducer rodhaving an actuation end; a first shear member having a first region ofreduced cross section dimension; a second shear member having a secondregion of reduced cross section dimension; a deployment mechanismmounted to the housing, the deployment mechanism including: a markerdeployment trigger accessible at an exterior of the housing; and anintroducer rod guide block attached to the actuation end of the markerintroducer rod, the introducer rod guide block being slidably disposedin the chamber of the housing, the introducer rod guide block beinglinked to the marker deployment trigger by the first shear member; and aretraction mechanism mounted to the housing, the retraction mechanismbeing configured to store a retraction force, and configured tofacilitate a retraction of both the cannula and the marker introducerrod into the chamber of the housing of the handle upon an actuation ofthe retraction mechanism, the retraction mechanism including: aretraction trigger accessible at the exterior of the housing; and acannula guide block attached to the proximal end of the cannula, theretraction force being applied to the cannula guide block, the cannulaguide block being slidably disposed in the chamber of the housing, theretraction trigger being linked to the cannula guide block by the secondshear member.
 50. The marker delivery device of claim 49, configuredsuch that upon actuation of the retraction trigger, the second shearmember is sheared at the second region of reduced cross sectiondimension by a retraction of the cannula guide block to permanentlydisconnect the retraction trigger from the cannula guide block, andconfigured such that the first shear member is sheared at the firstregion of reduced cross section dimension when the cannula guide blockimpacts the introducer guide rod block during retraction of the cannulaguide block, and when the first shear member is sheared the markerdeployment trigger is permanently disconnected from the introducer guiderod block.
 51. The marker delivery device of claim 49, the retractionmechanism including a spring located between the front end of thehousing and the cannula guide block to store the retraction force, thespring being in a compressed state prior to actuation of the retractiontrigger to provide a preload of the retraction force on the cannulaguide block, and configured to decompress to initiate the retraction ofthe cannula guide block within the housing to shear the second shearmember at the second region of reduced cross section dimension when theretraction trigger is actuated.
 52. The marker delivery device of claim49, wherein: the housing includes a trigger slot that extends through aside wall of the housing, the marker deployment trigger being mounted tothe housing for sliding movement along the trigger slot from an initialposition to a marker deployed position, the marker deployment triggerincludes a first lock member and the housing includes a second lockmember, and the first lock member permanently engages the second lockmember when the marker deployment trigger is positioned in the markerdeployed position.
 53. The marker delivery device of claim 49, wherein:the cannula has a flexible portion formed by a slot arrangement havingof a plurality of peripheral slots extending through a side wall of thecannula to the lumen, the plurality of peripheral slots being spacedapart to be substantially parallel along the lengthwise extent of thecannula to facilitate a flexure at the flexible portion of the cannula;and the marker introducer rod has a flexible region that corresponds tothe flexible portion of the cannula.
 54. A method of operating a markerdelivery device having a handle with a housing, a cannula, and a markerintroducer rod, the marker delivery device configured for deploying atissue marker, the method comprising: operating a retraction mechanismto effect a retraction of the cannula into a chamber of a housing of thehandle; and displacing a shear member to expose a shear region of theshear member to a retraction force exerted by the retraction mechanismto shear the shear member at the shear region to enable the retraction.55. The method of claim 54, wherein the retraction mechanism comprises aretraction trigger accessible at the exterior of the housing and acannula guide block attached to the proximal end of the cannula, theretraction force being applied to the cannula guide block, the cannulaguide block being slidably disposed in the chamber of the housing, theretraction trigger being linked to the cannula guide block by the shearmember to hold the cannula guide block stationary relative to thehousing of the handle, the method comprising: actuating the retractiontrigger to release the retraction force to retract the cannula guideblock; and shearing the shear member at the shear region during theretraction of the cannula guide block to permanently disconnect theretraction trigger from the cannula guide block.
 56. The method of claim55, wherein the retraction mechanism comprises a spring located betweenthe front end of the housing and the cannula guide block, the springbeing in a compressed state prior to actuation of the retraction triggerto provide a preload of the retraction force on the cannula guide block,and configured to decompress to initiate the retraction of the cannulaguide block within the housing to shear the shear member at the shearregion when the retraction trigger is actuated.
 57. The method of claim54, comprising: actuating the retraction mechanism for retracting boththe cannula and the marker introducer rod into the chamber of thehousing of the handle; and preventing a reversal of the retracting bythe shearing of the shear member.